[R] extraction from a list of vectors

Robert.Denham@dnr.qld.gov.au Robert.Denham at dnr.qld.gov.au
Mon Jun 18 03:35:29 CEST 2001

>> Jeff Miller <jmiller at xcaliber.com> writes:

>> 	It's easy to do this using a for loop, but I need something that
>> will be fast for lists 
>> 	with lengths of about 100,000. I've thought about using lapply, but
>> don't see how I can use it with "myidx". 
>> 	Thanks in advance, 
>> 		Jeff Miller 

> nothing similar for a list of vectors of unequal length. So if you
> need the speed badly, I think you have to go to the C level. (A rather
> nicely sized little exercise for learning the .External interface, I
> would expect.)

I also find that a bit of preprocessing of the data using perl is useful for
large dataset manipulations, particularly if its something you need to do
only at the start.

Robert Denham
Queensland Department of Natural Resources

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